However, in LQC/mLQCs, especially near the bounce, the evolution of the background is far from “slow", and its geometry is also far from the de Sitter.
In particular, for the perturbations during the bouncing phase,
the wavelengths could be larger, equal, or smaller than the corresponding characteristic scale, as it can be seen, for example, from Fig. REF . Thus, it is in general impossible to assume that the universe is in the
zeroth order adiabatic state at the bounce [1]}, [2]}, [3]}, [4]}, [5]}. Therefore, in the following let us first elaborate in more details about the subtle issues regarding the initial conditions.
